Retroreflectors, e.g., cube corner reflectors, are optical devices which reflect light back along the path from which it came. Optical tracking systems use retroreflectors to locate objects of interest. For example, a retroreflector can be affixed to the object of interest, which moves around within a frame of reference and is illuminated by a light source. Due to its retroreflective nature, the retroreflector returns light to the source, where it can be detected and located within the reference frame. However, in general, the retroreflected light contains no information about how the retroreflector (and correspondingly, the object of interest) is oriented in the reference frame.